A threat, and a very serious one at that. If somebody threatens to spin the wheel on you beware! The wheel is a devastating haymaker type punch that may very well take your head off.
However, due to the severity of 'the wheel' it is very rarely spun. 'Spinning the wheel' is no joking matter.
Sometimes called 'the wheel of justice'

One man may say to another who has wrongly cast doubts over his sexuality: "if you don't take that back I am going to spin the wheel"

spin the wheel: to spin the wheel is to try your luck with girls... similar to going to the casino, and trying your luck with the roulette or chocolate wheel. although in most attempts the casino gives better odds